Trump appeared to be referencing a story in The Daily Caller reporting that Abedin had forwarded State Department passwords to her personal Yahoo email account and that was likely compromised in subsequent breaches reported by the email provider.

The revelations are once again dredging up Clinton’s email controversy, which plagued the Democratic nominee throughout her campaign.

It's a fight Trump wants to have. Republicans have been eager to relitigate the controversy as part of an effort to distract from and undermine the special counsel investigation into whether Trump’s campaign colluded with Russia.

The Daily Caller report hinges on government emails made public as a result of litigation the conservative group Judicial Watch brought against the State Department in 2015.

The headline highlights a Aug. 2009 email released by State in September that appears to show Abedin, who served as vice chair on Clinton’s presidential campaign, forwarding passwords to her government laptop to her personal Yahoo account.

To be sure, the FBI said in documents related to the Clinton email probe that Abedin “routinely” forwarded emails from her official account to her personal one because it was easier to print.

Some of the emails cited by The Daily Caller contain information that was later determined to be classified, though none contain classified markings.

The article lays the groundwork for accusations that Abedin offered up sensitive information to hackers by detailing successive breaches at Yahoo, the first of which is now known to have impacted all 3 billion accounts in 2013.

A second, unrelated breach in 2014 exposed account information on 500 million users. The Justice Department has charged two Russian intelligence agents in connection with the case.

Cybersecurity experts cautioned that there is no evidence Abedin’s account was targeted by hackers.

“The classified information and other sensitive data was potentially exposed, but not definitely exposed based on what is known publicly,” said Ryan Kalember, a top executive at cybersecurity firm Proofpoint.

Still, her employment status would have made Abedin a top mark for a Russian spying operation. According to the criminal indictment, the hackers sought access to accounts of “Russian and U.S. government officials” on behalf of the FSB, Moscow’s federal security service.

“I don’t think it’s unreasonable to say her account was hacked,” said Megan Stifel, a cybersecurity expert at the Atlantic Council. “The State Department is obviously a very high target.”

According to State emails, Abedin’s computer would have required a FOB-generated password to access it, significantly reducing the likelihood a hacker could actually infiltrate her virtual desktop. However, any duplicate use of her passwords could have offered up other accounts to hackers.

Sources close to Hillary Clinton and Abedin say there's no official plan or strategy on how to deal with Abedin and the Yahoo controversy.

One source close to both women said Abedin is consulting a close group of confidants and her lawyers. And Clinton “really has nothing to do with this,” the source said.

“I'm sure she doesn't want to involve herself in any of it,” the source said. “I don’t see any scenario where HRC is hands-on with this stuff.”

Karen Dunn, Abedin's lawyer, referred inquiries to Nick Merrill, Clinton’s spokesman. Merrill did not respond to a request for comment.

Since Trump’s surprising 2016 win, he has frequently turned his attention to his former rival. In the last two months, he has mentioned her more than two dozen times on Twitter and mentions her during campaign-style rallies around the country. His supporters have frequently met the mentions with chants of "lock her up!"

They also give ammunition to those in the GOP looking to attack the FBI in an apparent effort to cast doubt on the Russia probe.

Some longtime Clinton advisers accused Trump of changing the subject.

“To be kept in mind is the ‘distract and deflect’ strategy at work on the part of the White House and its allies,” one adviser said. “The more focus is on allegations regarding Russia, the greater the effort to toss out allegations about the Clinton campaign and people.”

Other longtime Clinton advisers pushed back on Trump after his Tweet on Tuesday.

“Pick on someone your own size. Like Shamu,” Clinton's longtime spokesman Philippe Reines said in response to Trump's Tweet, referring to a famous killer whale. He later called the president a “prick.”